Arc lamp projector



OR Z 0 0 00" I60 May 7, 1935. KlEFER 2,000,760

ARC LAMP PROJECTOR gi Filed Jan. 19, 19:53

f I 1/ M1 V Inverfl'or' Johannes Kiefer' Patented May 7, 1935 UNITED STATES ARC LAMP PROJECTOR Johannes Kiefer, Berlin-Charlottenburg,

Ger-

many, assignor to General Electric Company, a corporation of New York Application January 19, 1933, Serial No. 652,544 In Germany January 28, 1932 4 Claims.

My invention relates to are lamp projectors and more particularly to searchlights.

In searchlights, such as are used for marine or aircraft detection purposes, for example, it is advantageous and at times necessary to obtain a wide beam of a uniformly high intensity. In projectors heretofore used, a spreading of the beam has been obtained by changing the distance between the arc and the reflector so as to defocus the arc and thereby spread the reflected rays. Such a spreading of the reflected rays, however, results in a substantial reduction in the intensity of the beam, which reduces the effectiveness thereof and makes the projector practically useless for many purposes.

It is therefore the principal object of my invention to provide a projector in which a spreading of the light beam may be obtained without an appreciable reduction of the beam intensity.

My invention will be better understood from the following description, when considered in connection with the accompanying drawing, and its scope will be pointed out in the annexed claims.

Fig. 1 of the accompanying drawing illustrates the mounting tof the two electrodes of a projector in accordance with my invention, and Fig. 2 illustrates diagrammatically a method of rotating the electrode mountings.

Referring to Fig. 1 in detail, the carbon l is the positive electrode and carbon 2 the negative electrode. The carbons are mounted in sleeves 3 and 4 respectively, which are rotated simultaneously about their respective axes 5 and 6. The carbons are mounted in accordance with my invention in holes I and 8, the axes 9 and ll) of which are spaced from and parallel to the axes 5 and 6 of the sleeves 3 and 4. It is not necessary to mount the carbons parallel to the axis of rotation, although it is preferable.

Fig. 2 illustrates one method of rotating the sleeves 3 and 4 including a motor i l and shaft l2 upon which gear i3 and worm i4 are mounted. The gear I3 engages gear I6 and rotates the sleeve 3 through shaft I1 and gears i8 and IS. The worm 14 engages gear 20 and rotates the sleeve 4 through shaft 2| and gears 22 and 23. When the motor is energized from any convenient source, the carbons l and 2 are rotated about the axes 5 and 6, causing the arc to travel in a circular path about axis 5 of the sleeve 3 which coincides with the focal axis of a reflector 25. The rapid movement of the are about the focal axis of the reflector results in a uniformly intense light source of increased size and thereby causes a spreading of the reflected beam without appreciably reducing its intensity.

It is of course obvious that it is not necessary to fully rotate the carbon sleeves. They may be oscillated over an arc of 180 or only 90, depending upon the beam spread or beam shape that is desired.

What I claim as new and desire to secure by Letters Patent of the United States, is,-

1. In an arc lamp, the combination of a reflector, a pair of cooperating electrodes, said electrodes being respectively movable laterally in relation to fixed axes, at least one of said axes coinciding with the focal axis of said reflector, and means for continually moving said electrodes during operation of said lamp.

2. In an arc lamp, the combination of a positiv and a negative carbon, rotatable sleeves for supporting said carbons, said carbons being spaced from the axis of rotation of said sleeves and means for rotating said sleeves.

3. In an arc lamp, the combination of a pair of rotatable sleeves, cooperating carbons respectively mounted in said sleeves, said carbons being spaced from and parallel to the axis of rotation of said sleeves and means for rotating said sleeves.

4. In an arc lamp, the combination of a reflector, a pair of rotatable sleeves, the axis of rotation of at least one of said sleeves being in the focal axis of said reflector, and a pair of cooperating electrodes mounted in said sleeves but spaced from said axes of rotation respectively and means for rotating said sleeves.

JOHANNES KIEFER. 

